Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments
Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediment...
Published in: | Paleoceanography and Paleoclimatology |
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Wiley-Blackwell Publishing Inc.
2022
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Online Access: | https://doi.org/10.1029/2022PA004433 http://ecite.utas.edu.au/155091 |
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ftunivtasecite:oai:ecite.utas.edu.au:155091 2023-05-15T13:24:14+02:00 Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments Bailey, I Hemming, S Reilly, BT Rollinson, G Williams, T Weber, ME Raymo, ME Peck, VL Ronge, TA Brachfeld, S O'Connell, S Tauxe, L Warnock, JP Armbrecht, L Cardillo, FG Du, Z Fauth, G Garcia, M Glueder, A Guitard, M Gutjahr, M Hernandez-Almeida, I Hoem, FS Hwang, JH Iizuka, M Kato, Y Kenlee, B Martos, YM Perez, LF Seki, O Tripathi, S Zheng, X 2022 application/pdf https://doi.org/10.1029/2022PA004433 http://ecite.utas.edu.au/155091 en eng Wiley-Blackwell Publishing Inc. http://ecite.utas.edu.au/155091/1/155091 - Episodes of early Pleistocene West Antarctic ice sheet retreat.pdf http://dx.doi.org/10.1029/2022PA004433 http://purl.org/au-research/grants/arc/DE210100929 Bailey, I and Hemming, S and Reilly, BT and Rollinson, G and Williams, T and Weber, ME and Raymo, ME and Peck, VL and Ronge, TA and Brachfeld, S and O'Connell, S and Tauxe, L and Warnock, JP and Armbrecht, L and Cardillo, FG and Du, Z and Fauth, G and Garcia, M and Glueder, A and Guitard, M and Gutjahr, M and Hernandez-Almeida, I and Hoem, FS and Hwang, JH and Iizuka, M and Kato, Y and Kenlee, B and Martos, YM and Perez, LF and Seki, O and Tripathi, S and Zheng, X, Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments, Paleoceanography and Paleoclimatology, 37, (7) Article e2022PA004433. ISSN 2572-4517 (2022) [Refereed Article] http://ecite.utas.edu.au/155091 Earth Sciences Oceanography Oceanography not elsewhere classified Refereed Article PeerReviewed 2022 ftunivtasecite https://doi.org/10.1029/2022PA004433 2023-03-20T23:17:23Z Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited ∼1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic 40Ar/39Ar ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to dirty icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a ∼366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the ∼41-kyr (inter)glacial world. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica eCite UTAS (University of Tasmania) Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell Paleoceanography and Paleoclimatology 37 7 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Oceanography not elsewhere classified |
spellingShingle |
Earth Sciences Oceanography Oceanography not elsewhere classified Bailey, I Hemming, S Reilly, BT Rollinson, G Williams, T Weber, ME Raymo, ME Peck, VL Ronge, TA Brachfeld, S O'Connell, S Tauxe, L Warnock, JP Armbrecht, L Cardillo, FG Du, Z Fauth, G Garcia, M Glueder, A Guitard, M Gutjahr, M Hernandez-Almeida, I Hoem, FS Hwang, JH Iizuka, M Kato, Y Kenlee, B Martos, YM Perez, LF Seki, O Tripathi, S Zheng, X Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
topic_facet |
Earth Sciences Oceanography Oceanography not elsewhere classified |
description |
Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited ∼1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic 40Ar/39Ar ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to dirty icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a ∼366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the ∼41-kyr (inter)glacial world. |
format |
Article in Journal/Newspaper |
author |
Bailey, I Hemming, S Reilly, BT Rollinson, G Williams, T Weber, ME Raymo, ME Peck, VL Ronge, TA Brachfeld, S O'Connell, S Tauxe, L Warnock, JP Armbrecht, L Cardillo, FG Du, Z Fauth, G Garcia, M Glueder, A Guitard, M Gutjahr, M Hernandez-Almeida, I Hoem, FS Hwang, JH Iizuka, M Kato, Y Kenlee, B Martos, YM Perez, LF Seki, O Tripathi, S Zheng, X |
author_facet |
Bailey, I Hemming, S Reilly, BT Rollinson, G Williams, T Weber, ME Raymo, ME Peck, VL Ronge, TA Brachfeld, S O'Connell, S Tauxe, L Warnock, JP Armbrecht, L Cardillo, FG Du, Z Fauth, G Garcia, M Glueder, A Guitard, M Gutjahr, M Hernandez-Almeida, I Hoem, FS Hwang, JH Iizuka, M Kato, Y Kenlee, B Martos, YM Perez, LF Seki, O Tripathi, S Zheng, X |
author_sort |
Bailey, I |
title |
Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
title_short |
Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
title_full |
Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
title_fullStr |
Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
title_full_unstemmed |
Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments |
title_sort |
episodes of early pleistocene west antarctic ice sheet retreat recorded by iceberg alley sediments |
publisher |
Wiley-Blackwell Publishing Inc. |
publishDate |
2022 |
url |
https://doi.org/10.1029/2022PA004433 http://ecite.utas.edu.au/155091 |
geographic |
Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell |
geographic_facet |
Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica |
op_relation |
http://ecite.utas.edu.au/155091/1/155091 - Episodes of early Pleistocene West Antarctic ice sheet retreat.pdf http://dx.doi.org/10.1029/2022PA004433 http://purl.org/au-research/grants/arc/DE210100929 Bailey, I and Hemming, S and Reilly, BT and Rollinson, G and Williams, T and Weber, ME and Raymo, ME and Peck, VL and Ronge, TA and Brachfeld, S and O'Connell, S and Tauxe, L and Warnock, JP and Armbrecht, L and Cardillo, FG and Du, Z and Fauth, G and Garcia, M and Glueder, A and Guitard, M and Gutjahr, M and Hernandez-Almeida, I and Hoem, FS and Hwang, JH and Iizuka, M and Kato, Y and Kenlee, B and Martos, YM and Perez, LF and Seki, O and Tripathi, S and Zheng, X, Episodes of early Pleistocene West Antarctic ice sheet retreat recorded by iceberg alley sediments, Paleoceanography and Paleoclimatology, 37, (7) Article e2022PA004433. ISSN 2572-4517 (2022) [Refereed Article] http://ecite.utas.edu.au/155091 |
op_doi |
https://doi.org/10.1029/2022PA004433 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
7 |
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1766378210054897664 |